Total hip arthroplasty (THA), also known as total hip replacement (THR), is the surgical replacement of the hip joint with an artificial prosthesis. The procedure involves the surgical excision of the head and proximal neck of the femur and removal of the acetabular cartilage and subchondral bone. An artificial canal is created in the proximal medullary region of the femur, and a metal femoral prosthesis is inserted into the femoral medullary canal. An acetabular component or implant is inserted proximally in the enlarged acetabular space.
THA is one of the most widely performed orthopedic procedures in the United States. It is estimated that about 170,000 THAs are performed each year in the United States, and about 300,000 worldwide.
One of the most important aspects of THA is ensuring proper alignment of the acetabular component or implant with respect to the pelvis. Specifically, studies have shown that failure to properly align the acetabular component or implant with the pelvis may lead to premature wear, propensity to dislocate and patient discomfort.